CSU researchers reduce forecast but continue to predict active 2022 Atlantic hurricane Season

FORT COLLINS, Colorado, Aug. 16 (TNSres) -- Colorado State University issued the following news release:

Colorado State University hurricane researchers have reduced their forecast slightly but continue to call for an above-average Atlantic hurricane season in 2022, citing the likely persistence of La Nina as a primary factor for the continued anticipation of an active season. Sea surface temperatures averaged across the tropical Atlantic and Caribbean are slightly warmer than normal. A warmer than normal tropical Atlantic provides more fuel for developing storms. However, sea surface temperatures are only slightly above normal, so the forecast team considers this a mostly neutral factor for the remainder of the season.

The tropical eastern and central Pacific currently has La Nina conditions; that is, the water temperatures are below average. CSU researchers anticipate that these waters will likely remain cooler than normal for the remainder of the Atlantic hurricane season. Consequently, they believe that El Nino is extremely unlikely this year. El Nino tends to increase upper-level westerly winds across the Caribbean into the tropical Atlantic, tearing apart hurricanes as they try to form.

The primary reason for the reduction in CSU's forecast from early July was a decrease in the statistical and statistical/dynamical model guidance that underpins these outlooks, along with some anomalous cooling in the subtropical Atlantic. When the subtropical Atlantic is cooler than normal, it can sometimes favor increased shear in the tropics, potentially counteracting some of the reduced shear typically observed in La Nina years.

18 named storms

The CSU Tropical Meteorology Project team is predicting 18 named storms in 2022, including the three named storms that have already formed (Alex, Bonnie and Colin). Of those, researchers expect eight to become hurricanes and four to reach major hurricane strength (Saffir/Simpson category 3-4-5) with sustained winds of 111 miles per hour or greater.

The team bases its forecasts on two statistical models, as well as three models that use a combination of statistical information and forecasts from dynamical models from the UK Met Office, the European Centre for Medium-Range Weather Forecasts and the Japan Meteorological Agency. These models are built on 25-40 years of historical hurricane seasons and evaluate conditions including: Atlantic sea surface temperatures, sea level pressures, vertical wind shear (the change in wind direction and speed with height in the atmosphere), El Nino (warming of waters in the central and eastern tropical Pacific), and other factors.

So far, the 2022 hurricane season is exhibiting characteristics similar to 1999, 2000, 2011, and 2021. "1999 was an extremely active Atlantic hurricane season, 2011 and 2021 were above-average seasons, and 2000 was a near-average season," said Phil Klotzbach, research scientist in the Department of Atmospheric Science and lead author of the report.

The team predicts that 2022 hurricane activity will be about 120% of the average season. By comparison, 2021's hurricane activity was also about 120% of the average season. The 2021 hurricane season had two landfalling continental US hurricanes, including Category 4 Hurricane Ida which battered Louisiana and then brought devastating flooding to the Mid-Atlantic and Northeast US.

The CSU team will issue a verification of all 2022 seasonal Atlantic hurricane forecasts in late November.

This is the 39th year that the CSU hurricane research team has issued an Atlantic basin seasonal hurricane forecast. The Tropical Meteorology Project team also includes Michael Bell, professor in the CSU Department of Atmospheric Science, and Alex DesRosiers, graduate research assistant in the same department. Bill Gray, who originated the seasonal forecasts, launched the report in 1984 and continued to author them until his death in 2016.

The CSU forecast is intended to provide a best estimate of activity in the Atlantic during the upcoming season - not an exact measure.

As always, the researchers caution coastal residents to take proper precautions.

"It takes only one storm near you to make this an active season," Bell said.

Landfalling probability included in report

The report also includes the probability of major hurricanes making landfall after 4 August:

* 68% for the entire U.S. coastline (full-season average for the last century is 52%)

* 43% for the U.S. East Coast including the Florida peninsula (full-season average for the last century is 31%)

* 43% for the Gulf Coast from the Florida panhandle westward to Brownsville (full-season average for the last century is 30%)

* 57% for the Caribbean (full-season average for the last century is 42%)

The forecast team also provides probabilities of named storms, hurricanes and major hurricanes tracking within 50 miles of each county or parish along the Gulf and US East Coast, as well as hurricane-prone coastal states, Mexican states, Canadian provinces and countries in Central America and the Caribbean. These probabilities for regions and countries are adjusted based on the current seasonal forecast and its projected effects on the upcoming hurricane season.

Funding for this year's report has been provided by Ironshore Insurance, the Insurance Information Institute, Weatherboy, IAA, First Onsite and a grant from the G. Unger Vetlesen Foundation.

Atlantic Basin seasonal hurricane forecast for 2022

Released August 4, 2022

Tropical Cyclone Parameters Extended Range

(1991-2020 Climatological Average Forecast for 2022

in parentheses)

Named Storms (14.4)/* 18/**

Named Storm Days (69.4) 85

Hurricanes (7.2) 8

Hurricane Days (27.0) 30

Major Hurricanes (3.2) 4

Major Hurricane Days (7.4) 8

Accumulated Cyclone Energy (123) 150

Net Tropical Cyclone Activity (135%) 160

Footnotes:

*/ Numbers in ( ) represent averages based on 1991-2020 data.

**/ Forecast numbers include storms that have already formed (Alex, Bonnie and Colin)

* * *

Original text here: https://newsmediarelations.colostate.edu/2022/08/15/csu-researchers-reduce-forecast-but-continue-to-predict-active-2022-atlantic-hurricane-season/